The watch was first issued for the Berkshires then extended east. It remains in effect until 9 p.m. Tuesday evening.

"Persons in these areas should be on the lookout for threatening weather conditions and listen for later statements and possible tornado warnings," Christopher Besse, of the Massachusetts Emergency Management Agency said in a statement.

A severe thunderstorm watch was issued for much of Eastern Massachusetts.

The National Weather Service warns "long-lived and intense" storms could feature strong, damaging winds, large hail and street flooding Tuesday.